There are tons of apps that can be downloaded and used in the classroom. One of my favorites is the Telling Time Quiz. Used independently, or in a group setting, it can be very motivational and a great daily or weekly practice for your students.
When locating the app, look for the picture shown above. It's free! My favorite way to use this app is with the whole class. I place the Ipad under the document camera so the kids can see it on the screen. They line up and off we go! The goal is to beat each level. Watch the video below to see the action.